package com.yfbao.horizon.encrypt.utils;


import lombok.extern.slf4j.Slf4j;
import org.apache.commons.codec.binary.Base64;
import org.apache.commons.codec.binary.Hex;
import org.apache.commons.io.output.ByteArrayOutputStream;

import java.io.ByteArrayInputStream;

/**
 * SM4加密与解密验证工具类
 * 对称加密
 * key为16进制32长度如:E6C63180C2806DD1F47B859DE501C15F
 */
@Slf4j
public class SM4Utils {
    private static final String EN_CODING = "UTF-8";

    /**
     * SM4ECB加密算法
     *
     * @param in       待加密内容
     * @param keyBytes 密钥
     * @return
     */
    public static String encrypt(byte[] in, byte[] keyBytes) {
        byte[] encrypted = encrypt2Byte(in, keyBytes);
        return Base64.encodeBase64String(encrypted);
    }

    /**
     * SM4ECB加密算法
     *
     * @param in       待加密内容
     * @param keyBytes 密钥
     * @return
     */
    public static byte[] encrypt2Byte(byte[] in, byte[] keyBytes) {
        return encrypt2Byte(in, keyBytes, true);
    }

    /**
     * SM4ECB加密
     *
     * @param in
     * @param keyBytes
     * @param isPadding
     * @return
     */
    private static byte[] encrypt2Byte(byte[] in, byte[] keyBytes, boolean isPadding) {
        try {
            SM4Context ctx = new SM4Context();
            ctx.isPadding = isPadding;
            ctx.mode = SM4.SM4_ENCRYPT;
            SM4 sm4 = new SM4();
            sm4.setkeyEnc(ctx, keyBytes);
            byte[] encrypted = sm4.cryptEcb(ctx, in);
            return encrypted;
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * SM4ECB加密不填充
     *
     * @param in
     * @param keyBytes
     * @return
     */
    public static byte[] encrypt2ByteNoPadding(byte[] in, byte[] keyBytes) {
        return encrypt2Byte(in, keyBytes, false);
    }

    /**
     * SM4的ECB加密算法
     *
     * @param content 待加密内容
     * @param key     密钥
     * @return
     */
    public static String encrypt(String content, String key) {
        try {
            byte[] in = content.getBytes(EN_CODING);
            byte[] keyBytes = (byte[]) new Hex().decode(key);
            return encrypt(in, keyBytes);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * SM4的ECB解密算法
     *
     * @param in       密文内容
     * @param keyBytes 密钥
     * @return
     */
    public static String decrypt(byte[] in, byte[] keyBytes) {
        try {
            byte[] decrypted = decrypt2Byte(in, keyBytes);
            return new String(decrypted, EN_CODING);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * SM4的ECB解密算法
     *
     * @param in
     * @param keyBytes
     * @return
     */
    public static byte[] decrypt2Byte(byte[] in, byte[] keyBytes) {
        return decrypt2Byte(in, keyBytes, true);
    }

    /**
     * SM4的ECB解密算法
     *
     * @param in
     * @param keyBytes
     * @return
     */
    public static byte[] decrypt2ByteNoPadding(byte[] in, byte[] keyBytes) {
        return decrypt2Byte(in, keyBytes, false);
    }

    private static byte[] decrypt2Byte(byte[] in, byte[] keyBytes, boolean isPadding) {
        try {
            SM4Context ctx = new SM4Context();
            ctx.isPadding = isPadding;
            ctx.mode = SM4.SM4_DECRYPT;

            SM4 sm4 = new SM4();
            sm4.setkeyDec(ctx, keyBytes);
            byte[] decrypted = sm4.cryptEcb(ctx, in);
            return decrypted;
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * SM4的ECB解密算法
     *
     * @param cipher 密文内容
     * @param key    密钥
     * @return
     */
    public static String decrypt(String cipher, String key) {
        try {
            byte[] in = Base64.decodeBase64(cipher);
            byte[] keyBytes = (byte[]) new Hex().decode(key);
            return decrypt(in, keyBytes);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    public static class SM4Context {
        public int mode;

        public long[] sk;

        public boolean isPadding;

        public SM4Context() {
            this.mode = 1;
            this.isPadding = true;
            this.sk = new long[32];
        }
    }

    public static class SM4 {
        public static final int SM4_ENCRYPT = 1;

        public static final int SM4_DECRYPT = 0;

        private long GET_ULONG_BE(byte[] b, int i) {
            long n = (long) (b[i] & 0xff) << 24 | (long) ((b[i + 1] & 0xff) << 16) | (long) ((b[i + 2] & 0xff) << 8)
                    | (long) (b[i + 3] & 0xff) & 0xffffffffL;
            return n;
        }

        private void PUT_ULONG_BE(long n, byte[] b, int i) {
            b[i] = (byte) (int) (0xFF & n >> 24);
            b[i + 1] = (byte) (int) (0xFF & n >> 16);
            b[i + 2] = (byte) (int) (0xFF & n >> 8);
            b[i + 3] = (byte) (int) (0xFF & n);
        }

        private long SHL(long x, int n) {
            return (x & 0xFFFFFFFF) << n;
        }

        private long ROTL(long x, int n) {
            return SHL(x, n) | x >> (32 - n);
        }

        private void SWAP(long[] sk, int i) {
            long t = sk[i];
            sk[i] = sk[(31 - i)];
            sk[(31 - i)] = t;
        }

        private static final byte[] SBOX_TABLE = {(byte) 0xd6, (byte) 0x90, (byte) 0xe9, (byte) 0xfe, (byte) 0xcc,
                (byte) 0xe1, 0x3d, (byte) 0xb7, 0x16, (byte) 0xb6, 0x14, (byte) 0xc2, 0x28, (byte) 0xfb, 0x2c, 0x05, 0x2b,
                0x67, (byte) 0x9a, 0x76, 0x2a, (byte) 0xbe, 0x04, (byte) 0xc3, (byte) 0xaa, 0x44, 0x13, 0x26, 0x49,
                (byte) 0x86, 0x06, (byte) 0x99, (byte) 0x9c, 0x42, 0x50, (byte) 0xf4, (byte) 0x91, (byte) 0xef, (byte) 0x98,
                0x7a, 0x33, 0x54, 0x0b, 0x43, (byte) 0xed, (byte) 0xcf, (byte) 0xac, 0x62, (byte) 0xe4, (byte) 0xb3, 0x1c,
                (byte) 0xa9, (byte) 0xc9, 0x08, (byte) 0xe8, (byte) 0x95, (byte) 0x80, (byte) 0xdf, (byte) 0x94,
                (byte) 0xfa, 0x75, (byte) 0x8f, 0x3f, (byte) 0xa6, 0x47, 0x07, (byte) 0xa7, (byte) 0xfc, (byte) 0xf3, 0x73,
                0x17, (byte) 0xba, (byte) 0x83, 0x59, 0x3c, 0x19, (byte) 0xe6, (byte) 0x85, 0x4f, (byte) 0xa8, 0x68, 0x6b,
                (byte) 0x81, (byte) 0xb2, 0x71, 0x64, (byte) 0xda, (byte) 0x8b, (byte) 0xf8, (byte) 0xeb, 0x0f, 0x4b, 0x70,
                0x56, (byte) 0x9d, 0x35, 0x1e, 0x24, 0x0e, 0x5e, 0x63, 0x58, (byte) 0xd1, (byte) 0xa2, 0x25, 0x22, 0x7c,
                0x3b, 0x01, 0x21, 0x78, (byte) 0x87, (byte) 0xd4, 0x00, 0x46, 0x57, (byte) 0x9f, (byte) 0xd3, 0x27, 0x52,
                0x4c, 0x36, 0x02, (byte) 0xe7, (byte) 0xa0, (byte) 0xc4, (byte) 0xc8, (byte) 0x9e, (byte) 0xea, (byte) 0xbf,
                (byte) 0x8a, (byte) 0xd2, 0x40, (byte) 0xc7, 0x38, (byte) 0xb5, (byte) 0xa3, (byte) 0xf7, (byte) 0xf2,
                (byte) 0xce, (byte) 0xf9, 0x61, 0x15, (byte) 0xa1, (byte) 0xe0, (byte) 0xae, 0x5d, (byte) 0xa4, (byte) 0x9b,
                0x34, 0x1a, 0x55, (byte) 0xad, (byte) 0x93, 0x32, 0x30, (byte) 0xf5, (byte) 0x8c, (byte) 0xb1, (byte) 0xe3,
                0x1d, (byte) 0xf6, (byte) 0xe2, 0x2e, (byte) 0x82, 0x66, (byte) 0xca, 0x60, (byte) 0xc0, 0x29, 0x23,
                (byte) 0xab, 0x0d, 0x53, 0x4e, 0x6f, (byte) 0xd5, (byte) 0xdb, 0x37, 0x45, (byte) 0xde, (byte) 0xfd,
                (byte) 0x8e, 0x2f, 0x03, (byte) 0xff, 0x6a, 0x72, 0x6d, 0x6c, 0x5b, 0x51, (byte) 0x8d, 0x1b, (byte) 0xaf,
                (byte) 0x92, (byte) 0xbb, (byte) 0xdd, (byte) 0xbc, 0x7f, 0x11, (byte) 0xd9, 0x5c, 0x41, 0x1f, 0x10, 0x5a,
                (byte) 0xd8, 0x0a, (byte) 0xc1, 0x31, (byte) 0x88, (byte) 0xa5, (byte) 0xcd, 0x7b, (byte) 0xbd, 0x2d, 0x74,
                (byte) 0xd0, 0x12, (byte) 0xb8, (byte) 0xe5, (byte) 0xb4, (byte) 0xb0, (byte) 0x89, 0x69, (byte) 0x97, 0x4a,
                0x0c, (byte) 0x96, 0x77, 0x7e, 0x65, (byte) 0xb9, (byte) 0xf1, 0x09, (byte) 0xc5, 0x6e, (byte) 0xc6,
                (byte) 0x84, 0x18, (byte) 0xf0, 0x7d, (byte) 0xec, 0x3a, (byte) 0xdc, 0x4d, 0x20, 0x79, (byte) 0xee, 0x5f,
                0x3e, (byte) 0xd7, (byte) 0xcb, 0x39, 0x48};

        public static final int[] FK = {0xa3b1bac6, 0x56aa3350, 0x677d9197, 0xb27022dc};

        public static final int[] CK = {0x00070e15, 0x1c232a31, 0x383f464d, 0x545b6269, 0x70777e85, 0x8c939aa1, 0xa8afb6bd,
                0xc4cbd2d9, 0xe0e7eef5, 0xfc030a11, 0x181f262d, 0x343b4249, 0x50575e65, 0x6c737a81, 0x888f969d, 0xa4abb2b9,
                0xc0c7ced5, 0xdce3eaf1, 0xf8ff060d, 0x141b2229, 0x30373e45, 0x4c535a61, 0x686f767d, 0x848b9299, 0xa0a7aeb5,
                0xbcc3cad1, 0xd8dfe6ed, 0xf4fb0209, 0x10171e25, 0x2c333a41, 0x484f565d, 0x646b7279};

        private byte sm4Sbox(byte inch) {
            int i = inch & 0xFF;
            byte retVal = SBOX_TABLE[i];
            return retVal;
        }

        private long sm4Lt(long ka) {
            long bb = 0L;
            long c = 0L;
            byte[] a = new byte[4];
            byte[] b = new byte[4];
            PUT_ULONG_BE(ka, a, 0);
            b[0] = sm4Sbox(a[0]);
            b[1] = sm4Sbox(a[1]);
            b[2] = sm4Sbox(a[2]);
            b[3] = sm4Sbox(a[3]);
            bb = GET_ULONG_BE(b, 0);
            c = bb ^ ROTL(bb, 2) ^ ROTL(bb, 10) ^ ROTL(bb, 18) ^ ROTL(bb, 24);
            return c;
        }

        private long sm4F(long x0, long x1, long x2, long x3, long rk) {
            return x0 ^ sm4Lt(x1 ^ x2 ^ x3 ^ rk);
        }

        private long sm4CalciRK(long ka) {
            long bb = 0L;
            long rk = 0L;
            byte[] a = new byte[4];
            byte[] b = new byte[4];
            PUT_ULONG_BE(ka, a, 0);
            b[0] = sm4Sbox(a[0]);
            b[1] = sm4Sbox(a[1]);
            b[2] = sm4Sbox(a[2]);
            b[3] = sm4Sbox(a[3]);
            bb = GET_ULONG_BE(b, 0);
            rk = bb ^ ROTL(bb, 13) ^ ROTL(bb, 23);
            return rk;
        }

        private void setkey(long[] SK, byte[] key) {
            long[] MK = new long[4];
            long[] k = new long[36];
            int i = 0;
            MK[0] = GET_ULONG_BE(key, 0);
            MK[1] = GET_ULONG_BE(key, 4);
            MK[2] = GET_ULONG_BE(key, 8);
            MK[3] = GET_ULONG_BE(key, 12);
            k[0] = MK[0] ^ (long) FK[0];
            k[1] = MK[1] ^ (long) FK[1];
            k[2] = MK[2] ^ (long) FK[2];
            k[3] = MK[3] ^ (long) FK[3];
            for (; i < 32; i++) {
                k[(i + 4)] = (k[i] ^ sm4CalciRK(k[(i + 1)] ^ k[(i + 2)] ^ k[(i + 3)] ^ (long) CK[i]));
                SK[i] = k[(i + 4)];
            }
        }

        private void oneRound(long[] sk, byte[] input, byte[] output) {
            int i = 0;
            long[] ulbuf = new long[36];
            ulbuf[0] = GET_ULONG_BE(input, 0);
            ulbuf[1] = GET_ULONG_BE(input, 4);
            ulbuf[2] = GET_ULONG_BE(input, 8);
            ulbuf[3] = GET_ULONG_BE(input, 12);
            while (i < 32) {
                ulbuf[(i + 4)] = sm4F(ulbuf[i], ulbuf[(i + 1)], ulbuf[(i + 2)], ulbuf[(i + 3)], sk[i]);
                i++;
            }
            PUT_ULONG_BE(ulbuf[35], output, 0);
            PUT_ULONG_BE(ulbuf[34], output, 4);
            PUT_ULONG_BE(ulbuf[33], output, 8);
            PUT_ULONG_BE(ulbuf[32], output, 12);
        }

        private byte[] padding(byte[] input, int mode) {
            if (input == null) {
                return null;
            }
            byte[] ret = (byte[]) null;
            if (mode == SM4_ENCRYPT) {
                int p = 16 - input.length % 16;
                ret = new byte[input.length + p];
                System.arraycopy(input, 0, ret, 0, input.length);
                for (int i = 0; i < p; i++) {
                    ret[input.length + i] = (byte) p;
                }
            } else {
                int p = input[input.length - 1];
                ret = new byte[input.length - p];
                System.arraycopy(input, 0, ret, 0, input.length - p);
            }
            return ret;
        }

        public void setkeyEnc(SM4Context ctx, byte[] key) throws Exception {
            if (ctx == null) {
                throw new Exception("ctx is null!");
            }

            if (key == null || key.length != 16) {
                throw new Exception("key error!");
            }

            ctx.mode = SM4_ENCRYPT;
            setkey(ctx.sk, key);
        }

        public void setkeyDec(SM4Context ctx, byte[] key) throws Exception {
            if (ctx == null) {
                throw new Exception("ctx is null!");
            }

            if (key == null || key.length != 16) {
                throw new Exception("key error!");
            }

            int i = 0;
            ctx.mode = SM4_DECRYPT;
            setkey(ctx.sk, key);
            for (i = 0; i < 16; i++) {
                SWAP(ctx.sk, i);
            }
        }

        public byte[] cryptEcb(SM4Context ctx, byte[] input) throws Exception {
            if (input == null) {
                throw new Exception("input is null!");
            }

            if ((ctx.isPadding) && (ctx.mode == SM4_ENCRYPT)) {
                input = padding(input, SM4_ENCRYPT);
            }

            int length = input.length;
            ByteArrayInputStream bins = new ByteArrayInputStream(input);
            ByteArrayOutputStream bos = new ByteArrayOutputStream();
            for (; length > 0; length -= 16) {
                byte[] in = new byte[16];
                byte[] out = new byte[16];
                bins.read(in);
                oneRound(ctx.sk, in, out);
                bos.write(out);
            }

            byte[] output = bos.toByteArray();
            if (ctx.isPadding && ctx.mode == SM4_DECRYPT) {
                output = padding(output, SM4_DECRYPT);
            }
            bins.close();
            bos.close();
            return output;
        }

//        public byte[] cryptCbc(SM4Context ctx, byte[] iv, byte[] input) throws Exception {
//            if (iv == null || iv.length != 16) {
//                throw new Exception("iv error!");
//            }
//
//            if (input == null) {
//                throw new Exception("input is null!");
//            }
//
//            if (ctx.isPadding && ctx.mode == SM4_ENCRYPT) {
//                input = padding(input, SM4_ENCRYPT);
//            }
//
//            int i = 0;
//            int length = input.length;
//            ByteArrayInputStream bins = new ByteArrayInputStream(input);
//            ByteArrayOutputStream bous = new ByteArrayOutputStream();
//            if (ctx.mode == SM4_ENCRYPT) {
//                for (; length > 0; length -= 16) {
//                    byte[] in = new byte[16];
//                    byte[] out = new byte[16];
//                    byte[] out1 = new byte[16];
//
//                    bins.read(in);
//                    for (i = 0; i < 16; i++) {
//                        out[i] = ((byte) (in[i] ^ iv[i]));
//                    }
//                    oneRound(ctx.sk, out, out1);
//                    System.arraycopy(out1, 0, iv, 0, 16);
//                    bous.write(out1);
//                }
//            } else {
//                byte[] temp = new byte[16];
//                for (; length > 0; length -= 16) {
//                    byte[] in = new byte[16];
//                    byte[] out = new byte[16];
//                    byte[] out1 = new byte[16];
//
//                    bins.read(in);
//                    System.arraycopy(in, 0, temp, 0, 16);
//                    oneRound(ctx.sk, in, out);
//                    for (i = 0; i < 16; i++) {
//                        out1[i] = ((byte) (out[i] ^ iv[i]));
//                    }
//                    System.arraycopy(temp, 0, iv, 0, 16);
//                    bous.write(out1);
//                }
//            }
//
//            byte[] output = bous.toByteArray();
//            if (ctx.isPadding && ctx.mode == SM4_DECRYPT) {
//                output = padding(output, SM4_DECRYPT);
//            }
//            bins.close();
//            bous.close();
//            return output;
//        }
    }

}
